383 cranking but no spark

[pennyduke]

Tried to fire up my new 383 today in my 93 Bayliner but I don't have any spark. I replaced the coil with a new Mercruiser coil and still nothing. I don't have the outdrive attached but other than that the only thing added was an electric fuel pump and safety switch. I do have the kill switch on the dash pushed down. Any suggestions where to start?

 

[Bt Doctur]

you need 12v at the purple wire at the coil first

 

[pennyduke]

So I've been working on this all day. I just got spark by disconnecting the white wire with the green stripe going to the shift linkage and the tan Tach wire on the negative side of the coil. When I plug the white/green back in I get no spark. What nlow?

 

[Bt Doctur]

The wire going to the shift interupter could be the culprit . Check to see how the wires are connected. You should have a long bolt that supplies the ground and a short screw that has the green/white wire. the top screw in the pic is the ground ,the bottom screw should have the green/white

 

[Fun Times]

I don't have any spark...I don't have the outdrive attached...

I just got spark by disconnecting the white wire with the green stripe going to the shift linkage.... When I plug the white/green back in I get no spark. What now?

Have you tried putting the shifter back into neutral gear (straight up and down)? When you remove / reinstall the Alpha outdrive, you have to go into forward gear to help make removing / reinstalling the outdrive easier and it helps avoid damage to the shifting components....Maybe the mercruiser shift interrupter switch is still activated.

 

[pennyduke]

I do not have the drive attached at this point. Yes the shifter is in neutral. This is a rebuilt 383 that I'm trying to get started for a 20 minute break in period. I think I will go ahead and start it today and look at the shift problem after I attach the outdrive for the river break in.You think that will be ok?

 

[Bt Doctur]

Except for the fact that you will have to shut the motor off everytime you want to get out of gear

 

[pennyduke]

So I still have a problem with spark. I went through the entire list in the sticky again and I get spark when I tap the white/green wire real quick to ground with a plug tester in the wire from the coil. I'm going to see if I can find a Ignition sensor today at West Marine. I will update you guys later. Thanks for all the help!!!

 

[pennyduke]

Success, This 383 sounds great. Did a 20 minute break in at 2000 rpm varying a little up and down. Next is a oil change and checking of all the fluid levels then to the river. Thank you all for the help over the last few years.

 

[NHGuy]

Congrats on the engine! Since you did a break in run I assume a flat tappet cam? Suggest some Defy engine oil or some zddp additive. It cuts sliding parts wear way down.
Quaker State Defy has the Zinc-dialkyl-dithiophosphate already in it. But you can get your own zddp if you have a different preferred oil. It is no longer used in the strength that it previously was. It's bad for catalytic converters. Something most boats don't have.

 

[pennyduke]

Sorry I didn't give details of my engine. Its a 1987 350 block bored 30 over with 1997 Vortec heads, Retro fit Roller Marine Cam, Roller lifters and a scat 383 stroker kit.

The machine shop said to use a zinc additive and prime the pump for 3 minutes then drop the dizzy in place and run it for 20 minutes at 1800-2200 rpm's. This will help seat the rings. Then change the oil with a small amount of zinc oil. Then take it to the river and set the timing and adjust the carb and try not to idle it for too long and run it at higher rpm's raising and lowering the rpm's about every 10 minutes for the first 10 hours. Change the oil again and don't go too wide open for the next 10 hours. I sure hope all this is right. See anything I missed?

 

[NHGuy]

The additive can't hurt, but it's not that neccesary with the roller valvetrain. The varied running is recommended, I tried to do it but I kept catching myself just droning along at a steady rpm. Mine is roller too. I have 25 hours now. I changed the oil after a very short run, maybe 10 minutes, basically did an oil gallery rinse run and oil pressure check.
I built my own engine and I am positive of every bearing and ring clearance. It's been very lively compared to the 350 mag stocker I took out.
If you have an alpha drive do not take off full power. The gears can't take it. I'd suggest high quality gear lube in the drive. I used Amsoil Severe Gear 75w110. No problems so far.

 

[pennyduke]

That's good advice on the outdrive. I did read that I need to be careful with it. Do you have a 383?

 

[NHGuy]

Yes, I went kind of full on with it. Long tube exhaust to allow a big cam. Dart heads. Roller lifters & rockers, beehive valve springs. High-ish compression.
I have been gently climbing it onto a plane with good results, no white chalky look to the drive. I might not even install the drive shower I bought.

 

[pennyduke]

That sounds awesome. I'm going to start a new thread with the motor running to try to find out where a rattling noise is coming from. Same noise as the old motor.

 

[pennyduke]

I still have a problem with the shift interrupt switch. When I unplug the white/green wire the boat starts and runs fine. If I try to plug it in while its running it kills the motor. The ground tab on the switch that the black wire hooks to pulls in and out a little. Does this sound like a bad switch staying grounded?

 

[Fun Times]

I still have a problem with the shift interrupt switch. When I unplug the white/green wire the boat starts and runs fine. If I try to plug it in while its running it kills the motor. The ground tab on the switch that the black wire hooks to pulls in and out a little. Does this sound like a bad switch staying grounded?

May want to try using a Multimeter to ohms test the switch and re-test it while wiggling the switch tabs too.

 

[pennyduke]

Is there a link to that part of the manual that shows how to ohm test it?

 

[Fun Times]

Is there a link to that part of the manual that shows how to ohm test it?

See if these two links helps you out any,

https://www.youtube.com/watch?v=W19Sao-FPVA

http://forums.iboats.com/forum/engi...errupter-switch-how-does-the-electronics-work